How are the Erlang/OTP applications packaged?

Yes, I believe all of them are in the installation (some may be excluded during compilation, if you are building from source). Perhaps not ose, which is OS-specific, so it won't work even if it is included.

All of them are included in the standard release from erlang.org and from Erlang Solution, or if you download the source and build it yourself. Which are included in various OS specific packages is up to them.